android跳过了44帧！该应用程序可能在其主线程上做过多的工作

如何解决android跳过了44帧！该应用程序可能在其主线程上做过多的工作

我正在使用Java和SQLite开发图书应用，我想在列表视图中显示内容列表。我已经解决了一些打开数据库的错误，但是现在数据库打开了，但是列表视图中什么都没有显示，我收到了该错误。

我的活动代码。单击主活动中的按钮后，此活动开始：

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.List;

public class LVSwitches extends AppCompatActivity {
public static final String LOGTAG="book";
private BookDataSource dataSource;
private List<season> seasons;
private ListView listView;
private ArrayAdapter<season> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_l_v_switches);
    listView = (ListView) findViewById(R.id.season_list);
    dataSource=new BookDataSource(getBaseContext());
    this.seasons = this.dataSource.getAllSeasons();
    //dataSource.getAllSeasons();
    if (seasons.size()==0){
        this.dataSource.CopyDbfile();

        this.seasons = this.dataSource.getAllSeasons();
    }

}

}

这是数据源的代码

public class BookDataSource {
private Context context;
private SQLiteDatabase database;
private SQLiteOpenHelper dbhelper;
private static String DB_PATH = "";
private static String DB_NAME = "lvs";

public BookDataSource(Context context){
    this.context=context;
    this.dbhelper=new bookDBHelper(context);
    DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
}
public void openDb(){
    database=dbhelper.getWritableDatabase();
    String myPath = DB_PATH + DB_NAME;
    database = SQLiteDatabase.openDatabase
            (myPath,null,SQLiteDatabase.NO_LOCALIZED_COLLATORS | SQLiteDatabase.OPEN_READWRITE);
    Log.i(LVSwitches.LOGTAG,"database opened");
}
public void closeDb(){
    if (database!=null){
        database.close();
        //Log.i(LVSwitches.LOGTAG,"database closed");
    }else {
       Log.i(LVSwitches.LOGTAG,"db=null");
    }
}
public List<season> getAllSeasons(){
    List<season> items=new ArrayList<season>();
    openDb();
    String[] colums= {bookDBHelper.KEY_ID,bookDBHelper.KEY_CONTENT,bookDBHelper.KEY_ISFAV};
    Cursor cursor=database.query(bookDBHelper.TABLE_LVS,colums,bookDBHelper.KEY_TYPE + " = \"" +bookDBHelper.TYPE_INDX + "\"",bookDBHelper.KEY_ID);
    if (cursor.moveToFirst()){
        do {
            season season = new season();
            season.setId(cursor.getLong(cursor.getColumnIndex(bookDBHelper.KEY_ID)));
            season.setStitle(cursor.getString(cursor.getColumnIndex(bookDBHelper.KEY_CONTENT)));
            season.setFav(cursor.getInt(cursor.getColumnIndex(bookDBHelper.KEY_ISFAV)) > 0);
            items.add(season);
        }while (cursor.moveToNext());

        }
    return items;
    }
    public void CopyDbfile()
    {
        try {
            InputStream in=this.context.getAssets().open("lvs.db");
            File dir=new File("/data/data/"+this.context.getPackageName()+"/databases");
            dir.mkdirs();
            FileOutputStream out=new FileOutputStream(new File(dir,"lvs.db"));
            byte[] buffer=new byte[1024];
            int len=0;
            while ((len=in.read(buffer))>0) {
                out.write(buffer,len);

            }
            in.close();
            out.close();
            Log.i(LVSwitches.LOGTAG,"database copied");

        }
        catch (Exception e){
            Log.i("Story","copy() : exception -> " + e.getMessage());
        }
    }



}

季节班：

    public class season {

    private String stitle="";
    private String pic="";
    private long id=0;
    private boolean isFav=false;
    public season(String stitle){
        this.id= id;
        this.stitle= stitle;
        this.isFav= isFav;
    }

    public String getStitle() {
        return stitle;
    }

    public void setStitle(String stitle) {
        this.stitle = stitle;
    }

    public season()
    {
        String stitle="";
        String pic="";
        long id=0;
        boolean isFav=false;
    }


    public String getPic() {
        return pic;
    }

    public void setPic(String pic) {
        this.pic = pic;
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public boolean isFav() {
        return isFav;
    }

    public void setFav(boolean fav) {
        isFav = fav;
    }
    public String toString(){
        return stitle;

    }
 }

解决方法

您需要告诉ListView使用您的数据源。您可以通过编写命令告诉它这样做

listView.setAdapter(YOUR_ADAPTER);

只需看一下Android文档。编写适配器已经很好地解释了。

此外，您提到了该应用程序在其主线程上执行过多工作的错误。它与您的ListView问题无关。这更是一条警告，告诉您在另一个线程上执行繁重的任务。主线程用于呈现您的应用程序。因此，如果您对此进行过多工作，则您的UI会被阻止。我建议您在另一个线程上执行数据库工作。此外，您应该记住，只有主线程才能将更改应用于UI，因此当您想要对UI线程上的并行线程的计算结果进行某些操作时，您可能会发现活动对象的runOnUiThread（）方法很有用。